To have the best chances of success, future-generation nuclear energy systems must fulfill a number of stringent criteria that are discussed by Euratom and the other partners in GIF. They should be licensed, constructed and operated so as to produce competitive and reliable energy, while satisfactorily addressing nuclear safety, waste, proliferation, and public perception concerns. In this context, Euratom is currently devoting parts of its research and training programme to innovative reactor designs (in particular, VHTR and GCFR) and to innovative fuel cycles (in particular, thorium). This overview paper describes elements of the strategy of Euratom research as well as some of its achievements in areas of interest for GEN IV.